iOS: Picking someone up at the airport? Enter their flight number into iPhone app Just Landed and—taking into consideration real-time flight data, your location, and current traffic—it will send you an alert when it's time to leave the house for a seamless, no-waiting airport pickup.

When it's almost time to leave, Just Landed sends you a "leave in five minutes" notification to give you a little prep time, then a "leave now" notification when you should be out the door. Additionally, the app delivers notifications for early, delayed, diverted, or canceled flights, terminal changes, and take-off and landing notifications complete with fun aircraft sounds.

Regarding the app's ability to deliver an accurate estimate of drive time, developer Jon Grall says:

...the app updates your location in the background—we use the significant location change feature of iOS to monitor whenever you change cell towers (i.e. not creepy stalking) so that we can keep all your reminders up to date in case you move location and we need to adjust the driving time to the airport. We also check traffic conditions in advance of landing in case we need to adjust reminders for rush hour.

It just hit the App Store, and it's free for a limited time. I haven't been able to try it out for an actual pickup yet (though I tested a flight coming into LAX that I'm not picking someone up for and the estimate looks right to me), but in theory, it's a clever idea that (potentially) solves a very common problem. If you're hoping for an Android version, Grall says, assuming the iOS app does well, an Android version is likely.